In the prior art to control semiconductor switching element for power supply, the control circuit memorizes the data showing the operation status of semiconductor switching element for electric power one by one as the longitudinal data. As a result, because the control delay is canceled, the voltage change caused at the turn-off (or, the turn-on) is surely controlled.
In this prior art, the operation status data that shows the operation of the semiconductor switching element for the electric power at the turn-off (or, the turn-on) is memorized one by one as the longitudinal data.
And, the control circuit predicts the operation of the semiconductor switching element for the electric power at the next turnoff (or, the turn-on) based on this operation status data.
After this, the control circuit sets the voltage at the next turnoff (or, the turn-on) so that the change of the overshoot (or, the undershoot) may decrease based on this prediction result.
Moreover, in the DC/DC converter, to achieve the quick regulation (control with a high response), the control circuit can predict the off time of the switch for the current control for instance.
The control circuit samples the current of the switch twice for on a period, and detects the increasing rate of the current, and predicts the time when the current of the switch reaches a preset threshold value (value that changes according to the load) based on this detection value, and can turn off the switch at this time.    [patent documents] JP 2006-42565